Diodes Incorporated PI7C9X7952BFDEX

Overview

PI7C9X7952BFDEX from Diodes Incorporated is a PCI Express® 1.1-compliant dual UART bridge IC with integrated PCIe endpoint logic, two independent 16C950-compatible UART channels, 128-byte transmit/receive FIFOs, and configurable GPIOs. It operates at 2.5 GT/s, supports MSI interrupts, and delivers up to 15 Mbps per UART channel using programmable baud rate generators. It is used in industrial PCs, embedded controllers, and communication gateways requiring legacy serial port expansion over PCIe.

For engineers reviewing the PI7C9X7952BFDEX datasheet, PI7C9X7952BFDEX pinout, PI7C9X7952BFDEX application, or PI7C9X7952BFDEX equivalent, key selection criteria include PCIe endpoint compliance level, UART FIFO depth, GPIO count, EEPROM configuration interface support, and industrial temperature operation (–40°C to +85°C).

Technical Context

The PI7C9X7952BFDEX implements a PCIe-to-parallel-bridge architecture with dedicated configuration space for both PCIe root complex interaction and per-UART register access. It supports PCIe Link Training and Status State Machine (LTSSM), Message Signaled Interrupts (MSI), and Power Management States L0–L2/L3ready.

Each UART channel features full 16C950 register compatibility, including Line Control Register (LCR), Modem Control Register (MCR), and Enhanced Feature Register (EFR), enabling drop-in replacement of legacy UART controllers in BIOS/UEFI and OS driver stacks without modification.

Key Specifications

Pinout & Package

PI7C9X7952BFDEX is housed in a 160-pin LFBGA package (12 mm × 12 mm, 0.8 mm pitch) with exposed thermal pad. Pin assignments are defined per Section 4.1 of DS40129 Rev 1.8.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual UART PCIe bridge applications.

Compared with XR17V352IL-F and PI7C9X7951BQFEX, the PI7C9X7952BFDEX uniquely balances PCIe 1.1 compatibility, industrial temperature range, EEPROM-configurable identity, and dual 128-byte FIFOs - making it optimal for cost-sensitive, field-deployed embedded systems requiring long-term supply stability.

Availability

PI7C9X7952BFDEX is available at Aetrix Electronics and suitable for industrial PC expansion, POS terminal integration, and telecom gateway management requiring stable component supply across multi-year production cycles.

Supply support for PI7C9X7952BFDEX includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, specializing in power management, signal integrity, and connectivity solutions for industrial, computing, and communications markets.

The PI7C9X7952BFDEX belongs to Diodes' PCI Express bridge product line, designed specifically to enable legacy serial interface retention in modern PCIe-based platforms while minimizing FPGA or ASIC dependency.

FAQ

Does PI7C9X7952BFDEX require external EEPROM to function?

No. The PI7C9X7952BFDEX operates with default configuration values stored in internal ROM. External EEPROM is optional and used only to override vendor/device IDs, subsystem parameters, and GPIO default states. Boot proceeds normally without EEPROM presence.

Can both UART channels operate at different baud rates simultaneously?

Yes. Each UART channel has independent baud rate generator registers (DLL/DLH and prescaler), allowing simultaneous operation at distinct rates - e.g., UART0 at 115.2 kbps for a modem and UART1 at 921.6 kbps for a barcode scanner - with no cross-channel interference.

Is PI7C9X7952BFDEX compatible with Linux kernel drivers?

Yes. It is supported natively by the Linux '8250_pci' driver since kernel v4.12. The device enumerates as a standard PCI serial controller with two ports (/dev/ttyS2 and /dev/ttyS3), and all 16C950 registers are accessible via standard ioctl() calls.

What is the maximum sustained data rate per UART channel?

The maximum sustained data rate is 15 Mbps per channel, verified under worst-case conditions (128-byte FIFO, no flow control, continuous transmission). This assumes clean signal integrity on TXD/RXD lines and proper termination per RS-422/485 standards.